wired/interconnected smoke detectors: any low voltage models?

[micrologix1500]

I have been working on an addition to my home. On the permit it states that I must install "hardwired/interconnecting smoke detectors required throughout the entire dwelling per 2003 M.R.C.". I did a little web research into this, and was surprised to only find ones powered from 120VAC. Aren't there any low-voltage models? Seems to me that the line voltage is going to get dropped and rectified anyway, and I would imagine that a low-voltage system would simplify and cheapen the interconnect wiring scheme over a 120VAC system.

[EXT]

I don't know of low voltage models, but I have the line voltage ones in my house. All it takes is a 3 wire (plus ground) cable between the smoke detectors, the black and white provide power and the red is the trigger that sets all of them off. They work great.

[J.A. Michel]

Hardwired implies that it is connected to your home's electrical power. I don't know of any low-voltage models, but if there were, they would not be any easier to install - because you would still have to wire them regardless.

It's not too hard to install the 120V models. Pull one circuit using 14/3 Romex with ground. Use black for hot, white for neutral, and the red wire for signal between smoke detectors.